Alternatively, the resonance \(X_{0}\)  was analyzed in Refs. [1]}, [2]}, [3]}, [4]} by assuming that it
is a diquark-antidiquark state. The sum rule prediction for the mass of the
scalar tetraquark \(T_{1}=[sc][\overline{u}\overline{d}]\)  with an axial-axial
\(C\gamma _{\mu }\otimes \gamma ^{\mu }C\)  type  structure reads [2]}
\(m_{T_{1}}=(2910\pm 120)~\mathrm {MeV}.\) 
